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Jeremy, Certified Truck/Bus Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 3320
Experience:  ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, EPA 608/609 HVAC Certified, Steering/Suspension and ABS/Brakes Technician
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I have a tripac and it has the code AL and what looks like

Customer Question

I have a tripac and it has the code AL and what looks like an upside down w2ill start and run for about 4 min then shut off
JA: We'll do all we can to help. Tell me a bit more about what's going on so the Heavy Equipment Mechanic can help you best.
Customer: it doesn't require resetting the breaker like it does when 5the engine doesn't start
JA: Is there anything else the Heavy Equipment Mechanic should be aware of?
Customer: it seems to run good for those 4 min
JA: Our top Heavy Equipment Mechanic is ready to take your case. Just pay the $5 fully refundable deposit and I'll fill the Heavy Equipment Mechanic in on everything we've discussed. You can go back and forth with the Heavy Equipment Mechanic until you're 100% satisfied. We guarantee it.
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Expert:  Jeremy replied 1 year ago.

My name is ***** ***** I will assist you with your question today.

I'm an independent contractor and I don't get paid until a rating has been made. No rate, site gets it all.

We can go back and forth as needed to help resolve the issue you are having. Follow ups are free after ratings, so rate in confidence!

That would be a alternator failure alarm. Have the alternator tested. I am posting info below for you.

Diagnostic Procedure
1. Check alternator output with a meter. With the engine running the voltage at the alternator output should
be approximately 13.8 to 14.2 Vdc. If the voltage is less than 12.6 Vdc or greater than 15 Vdc with the
engine running test and repair the alternator.
2. Check for broken or slipping alternator belt.
3. Check that all alternator connections are clean and secure. Be sure that the 2A circuit at the alternator
is not loose or corroded.
4. Check the condition of the tractor batteries. A defective tractor battery can cause this alarm.
5. Check the D+ circuitry for shorts using the drawing on the next page.

[ALt] Alternator Alarm
Note 1 Note 1 On engine startup, initial alternator
excite voltage is supplied from the D+
terminal on the Interface Board to the
alternator excite terminal.
3 minutes after engine startup, the Interface
Board monitors the voltage at the D+
terminal. If the alternator voltage regulator
detects a fault, the alternator excite
terminal is grounded. If the D+ voltage at
the Interface Board is low or missing after 3
minutes of engine operation, the [ALt]
Alarm Code is set.
Partial Schematic Diagram - [ALt] Alarm Code
D+ 2A
To Starter
and Battery

This flowchart illustrates the conditions that will cause the engine to start, the engine start sequence and the
conditions that will cause the engine to shut down.
Optional Arctic Switch
Coolant temp is < 30°F (-1°C)
Battery Voltage
Battery voltage is < 12.15 Vdc
for 60 seconds
HMI Control Panel
Air conditioning selected and
cab temp > 5°F above setpoint
Eng Temp Thermistor
Determines Preheat Time
(Discontinued 03/2008)
Preheat Relay
Time determined by Thermistor
(33 seconds after 03/2008)
Run Relay
Optional Arctic Switch
Coolant temp is > 55°F (13°C)
Reset Switch
Engine Protection
Fuel Pump
Supplies fuel to
fuel solenoid
Fuel Solenoid
Features Pull-in
and Hold Coils
Starter Solenoid
Flywheel Sensor Starter
Battery Voltage
Battery voltage is > 13.56 Vdc
for 15 minutes
HMI Control Panel
Air conditioning selected and
cab temp at setpoint for 15 min
Any single condition will cause an engine start
All conditions must be satisfied before the engine will shut down
Engine Shutdown
Engine Start Engine Start
Starter Relay
Hold Pull-In

Clearing Alarm Codes
Cycling the HMI Control Panel Main Power off and back on will clear the alarm code. First, record the alarm code
shown in the display. Use the HMI Control Panel Main Power On/Off key to turn the TriPac unit off. Resolve the
condition that caused the alarm and turn the HMI Control Panel Main Power On/Off key back on.


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Customer: replied 1 year ago.
I checked it out and it was a broken wire thank you for your heip
Expert:  Jeremy replied 1 year ago.

You're welcome.

Expert:  Jeremy replied 1 year ago.

I see you viewed this and this is still showing as an open question due to no positive (3 stars or more) rating.

Were you not pleased with my service to you or is there a rating issue? Please let me know if you still need assistance with this, if there is a rating issue, and/or you need more time to respond.

I like to make sure all my customers are satisfied since you did pay a deposit for me to assist you, whether I’m paid by a positive rating feedback or not.

We can continue where we left off or start over if needed. Also, if you need diagrams, instructions, etc please don’t hesitate to ask.

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